1. Field of the Invention
The present invention relates to surgical instruments for performing laparoscopic and endoscopic surgical procedures, and more particularly to a device for securing instruments such as cannulas in an incision in a patient's body during the surgical procedure.
2. Discussion of the Prior Art
In recent years, laparoscopic and endoscopic surgical procedures have become increasingly popular for performing major surgical operations. In such a procedure, a small incision or puncture is made in the patient's body to provide access for a tube or a cannula device. The tube or cannula device is inserted into the patient's body to allow for the insertion of instruments used in performing the surgical procedure, as well as for the insertion of a camera or endoscope to view the surgical objective.
Typically, a trocar device including, for example, an obturator and a cannula is employed to puncture the skin and provide access to the surgical area. A pointed obturator may be used for penetrating the skin to extend the trocar beyond the body wall to the surgical site. Alternatively, an incision may be made using a scalpel or similar device before inserting a blunt obturator through the incision. When either obturator is removed, the cannula remains in place to maintain access to the surgical site, and several incisions may be made to provide numerous access ports to the surgical objective. Once the cannulas are in place, various surgical instruments such as scissors, dissectors, retractors or the like, may be inserted by a surgeon to perform the surgery. Typically, a scope device is used to view the area directly, or a miniature camera is used to display the surgical site on a video monitor in the operating room.
The primary benefit of such minimally invasive surgical techniques is the reduction of scarring, and consequently, minimizing damage to surrounding tissue and organs. As a result, recovery time is greatly reduced for the patient.
During a laparoscopic surgical procedure, gas is introduced into the body cavity, usually the abdomen, by means of a pneumoperitoneum needle. The gas inflates the abdominal cavity to provide greater access to the surgical area and minimize obstruction during surgery. The trocar assembly is then inserted into the body cavity to a point adjacent the tissue or organ which is the surgical objective. Due to the gas insufflation, it is necessary to maintain a desired gas seal at each of the cannulas in position in the body. After the obturator is removed from the trocar assembly, the cannula remains in place in the patient's body. Ordinarily, a flapper valve in a housing at the proximal end of the cannula prevents the insufflation gas from escaping through the cannula after the obturator is removed. It is also preferred to maintain the cannulas in a relatively stable state, primarily to free the surgeon and the surgical assistants from having to hold the cannulas to prevent these instruments from backing off and consequently being displaced from the incision. Furthermore, the routine movement of the cannulas during the surgical procedure may result in a loss of gas tightness about the cannula, thereby negatively effecting the surgical procedure.
In order to support the cannula in a hands-off manner, and maintain the integrity of the gas seal at the incision, it has been known to provide various mechanisms and devices which attempt to maintain and secure the cannula in the incision.
Typical devices include penetration limiting devices such as the sleeve or collar disclosed in U.S. Pat. No. 3,817,251 to Hasson, which provides a conical sleeve which may be adjusted to various positions on the cannula to limit insertion of the cannula to specific depths. U.S. Pat. No. 4,077,412 to Moossun, U.S. Pat. No. 4,637,814 to Leiboff, as well as U.S. Pat. No. 4,627,838 to Cross et al., disclose devices to prevent the inadvertent removal or backing off of the cannula during the surgical procedure. Moossun provides an inflatable diaphragm member which is inflated once the cannula is positioned in the body cavity to prevent inadvertent removal of the cannula from the incision until the diaphragm is deflated. Leiboff also discloses an inflatable cuff member which is inflated in a body cavity to secure the device and seal the cavity at the opening to prevent leakage of irrigating fluid during an irrigation procedure. Cross et al. provide a complex wing-type mechanism which is extended once the catheter is positioned within the body cavity so that the wing members engage the body wall to prevent removal of the catheter until the wing mechanism is collapsed. These devices often require additional equipment to be present in the operating room, such as a gas or compressed air source to inflate the device.
Also known are sleeve members having external ribs which fit over a cannula. The sleeve is forced into the incision either by twisting or simply by forcing the sleeve into the incision along with the catheter. Further, devices are known that include a "Malecott" type wing arrangement such as U.S. Pat. 4,608,965 to Anspach, Jr. et al. Anspach discloses an endoscopic retainer and tissue retracting device including a cylindrical tube having flexible strips at a distal end. The device is placed over an endoscope and the retracting device's flexible strips are expanded by a surgeon to retract tissue and retain the endoscope in position.
The novel tissue gripping device of the present invention obviates the disadvantages encountered in the prior art and provides improvements which are desirable for enhancing the retention properties of the cannula in the body wall. The device of the present invention provides a tissue gripping device which may work in concert with a cannula to retain the cannula in the body wall through the provision of articulated flexible members which extend outwardly to engage the body wall when in their extended position. The device includes means to positively retain the flexible members in an extended position so that the cannula is maintained in the body wall without the requirement of having surgical personnel hold the cannula in place.